Axis 2 : Biology of adaptation

This axis aims at understanding the nature and mechanisms of adaptation to natural environmental gradients but also to anthropogenic alterations of natural biota. It is organized around three key challenges.
Genetic basis of adaptation

We seek to understand the genetic basis of adaptation in natural conditions, by studying plant and insect populations distributed along environmental gradients (e.g. elevation gradients), or experiencing drastic natural or anthropogenic selection pressures (climate forcing, pollution, insecticides). This also implies exploring the effects of phenotypic plasticity by studying gene regulation and epigenetics, and how this plasticity contributes to phenotypic variation and individual acclimatization to novel environmental pressures. This bears important applications towards understanding past and ongoing adaptations to global changes, better managing genetic resources for animal breeding and improving the control of pest or invasive species.

Keywords : genome-scans, genome-wide association studies, quantitative genetics, environmental gradients, pollutants, transcriptomics, epigenetics

 

Keywords : hybrid zones, clines, ecological speciation, gene mosaics, genetic architecture, linkage disequilibrium, phylogenetic comparative methods, mate choice, behaviour
Mechanisms and scenarios of speciation

We aim at studying the adaptation of populations to various environmental gradients or constraints, quantify the balance between disruptive selection and homogenizing gene-flow, and how these alternative processes shape hybrid zones or genetic divergence along the speciation continuum — this is mainly conducted on alpine plants (both tropical and temperate) and butterflies. This involves the inference of genomic signatures of adaptive divergence between sister species, and the inference of phylogenetic signatures of adaptive radiation in recently diversified clades. In particular, we seek for sympatric divergence of functional traits between closely related species, such as traits involved in reproductive isolation or niche differentiation, as indicators of ecological speciation.

 

Experimental study of plasticity and acclimatization

We aim at understanding the mechanisms of adaptation using experimental approaches of ecophysiology and functional genomics, across different biological scales, i.e. the ones of organisms (toxicity, tolerance/resistance, growth, fecundity, melanism, life history traits, ...) and sub-organisms (genomic variations, gene expression, metabolism, physiology). This implies working on the long-term impacts of stressors (eg, pollutants, UV, temperature...), in controlled experiments using laboratory-reared animal models. We also study the joint effect of multiple environmental stressors, and across several generations of individuals.

Keywords : RNAseq and other omics techniques, epigenetics, DNA metabarcoding, biochemistry, physiology, isotopic analyses, transgenerational effects

 

Key papers :
  • Capblancq T, Després L, Mavárez J (2020) Genetic, morphological and ecological variation across a sharp hybrid zone between two alpine butterfly species. Evolutionary applications 13 (6), 1435-1450
  • Cattel J, Haberkorn C, Laporte F, Gaude T, Cumer T, Renaud J, (…), Bonneville JM, (...), David JP (2020) A genomic amplification affecting a carboxylesterase gene cluster confers organophosphate resistance in the mosquito Aedes aegypti from genomic. Evolutionary Applications, early view
  • Sherpa S, Blum MGB , Després L (2019) Cold adaptation in the Asian tiger mosquito’s native range precedes its invasion success in temperate regions. Evolution 73 (9), 1793-1808
  • Prud’Homme SM, Renault D, David JP, Reynaud S (2018) Multiscale Approach to Deciphering the Molecular Mechanisms Involved in the Direct and Intergenerational Effect of Ibuprofen on Mosquito Aedes aegypti. Environmental science & technology 52 (14), 7937-7950
  • Alberto FJ, Boyer F, (...), … Pompanon F (2018) Convergent genomic signatures of domestication in sheep and goats. Nature Communications 9 (1), 813
  • Regnault C, Usal M, Veyrenc S, (…), Raveton M, Reynaud S (2018) Unexpected metabolic disorders induced by endocrine disruptors in Xenopus tropicalis provide new lead for understanding amphibian decline. Proc Natl Acad Sci USA, 115(19)